The present invention relates to an apparatus for evaluating the performance of catalysts by determining the kinds and concentrations of the gases formed in a reaction of starting materials in the presence of the catalyst.
To evaluate the performance of a solid catalyst in the gas phase chemical reaction, gas chromatography has been used for analyzing reaction products. The gas chromatography process comprises a gaseous mobile phase for carrying a multi-component product and a stationary phase for retaining the components of the product for separation, and separates the product into components by the differences in characteristics of each component relative to the stationary and mobile phases. The separated components are identified by a qualitative detector such as a mass spectrometer, and/or the concentrations or masses are determined by a quantitative detector such as an flame ionization detector.
Catalyst performance is evaluated by the gas chromatography, measuring the temperature of the catalyst at which the gaseous chemical reaction starts or determining the relative amounts of the useful and useless products.
The gas chromatography is an excellent method in that multi-component products can be precisely analyzed. However, it requires at least several ten minutes for a single analysis step due to theoretical restriction, and it is impossible to evaluate plural catalytic products concurrently with a single apparatus. Accordingly, on evaluation of the performance of a plurality of catalysts, it is necessary to carry out a time-consuming analysis and evaluation for each catalyst, which is extremely laborious.
Combinatorial chemistry is a procedure for developing a new material or product and is receiving attention in the field of pharmaceuticals and other functional materials. Tn the catalyst-related field, a catalyst-developing procedure which utilizes the concept of combinatorial chemistry has recently been noted. In the combinatorial chemistry, a large amount of catalyst candidate is prepared at a time and evaluated. The most important requirement in the application of the combinatorial chemistry to this field is the quick analysis and quantitative determination of the compounds formed by the catalytic reaction. Since the gas chromatography so far widely used as the procedure for analyzing the gas formed by reaction is expensive and requires relatively a long time for analysis, it cannot meet the time requirement essential in the combinatorial chemistry.
The present invention has been accomplished to solve the above drawbacks of the prior art, and an object thereof is to provide an apparatus with which evaluation of catalyst performances of plural catalysts can be made concurrently, quickly and in simple steps.
In order to attain the above object, the present invention provides an apparatus for elvaluating catalyst performance comprising:
a vessel in which a plurality of catalysts are disposed at a predetermined distance;
a supply device for supplying a reactant gas into the vessel;
a plurality of measuring instruments provided with at least one gas sensor for each of the catalysts, each gas sensor detecting the formed gas individually by the contact of the reactant gas with the catalysts, and outputting signals according to the kind and concentration of the formed gas; and
a calculating unit for identifying the kind of the formed gas and calculating the concentration thereof based on the output signal of the plurality of the measuring instruments.
Since the apparatus of the present invention brings the reactant gas into a plurality of catalysts at a time and detects the formed gas on each catalyst, it is possible to evaluate the performance of the plurality of catalysts concurrently. Further, since the gas sensors used for sensing formed gases have quick response, cheap price, and simple structure, the evaluation of performance of catalysts can be made quickly and in simple steps. Accordingly, analysis and quantitative determination of a large amount of catalyst candidate materials by combinatorial chemistry can be performed in a short time. Consequently, the catalyst development, which had hitherto required a long time, can be accelerated.
According to a preferred embodiment of the present invention, the plurality of measuring instruments are respectively provided with a plurality of gas sensors, and the calculating unit calculates the concentration of the formed gas by comparing the output values of the gas sensors taken by a preliminary measurement of a plurality of gases whose kinds and concentrations are known, with the output values of the gas sensors taken by a measurement of the formed gas.
In a further preferred embodiment of the present invention, the plurality of measuring instruments are respectively provided with a plurality of gas sensors, and the calculating unit identifies the kinds of the formed gas and calculates the concentration thereof by comparing the patterns of output values of the gas sensors taken by a preliminary measurement of a plurality of gases whose kinds and concentrations are known, with the patterns of output values of the gas sensors taken by a measurement of the formed gas.
According to the above preferred embodiment, a plurality of gas sensors are used to identify the kind of the formed gas by the comparison With the output values of the gas sensors taken by measurement of gases whose kinds and concentrations are known or by the matching with the patterns of the output values and calculate the concentration of the formed gas, analysis precision can be improved in comparison with the analysis using a single gas sensor. Furthermore, according to the present invention, the kind of the formed gas is identified and the concentration of the formed gas is calculated by the comparison with the known amount as in the pattern matching process, the analysis of the formed gas can be performed quickly.
In a further preferred embodiment of the present invention, the apparatus for evaluating catalyst performance further comprises a plurality of suction apparatuses, provided in the vicinity of each of the plurality of catalysts, for sucking the formed gas and leading the formed gas to the measuring instruments
According to the above embodiment, the gas formed under each of the catalysts is sucked immediately after the formation by a suction apparatus provided in the vicinity of each catalyst, the possibility for the formed gas to be mixed with the gas formed under other catalysts and led to the measuring instrument in mixture is reduced, and the analysis precision can be improved.
The other objects and features of the present invention will become apparent from the following description accompanied by drawings. It is to be understood that the present invention is not to be limited to the following embodiments but be modifiable in various manners within the scope of the claims.